Here today, gone tomorrow

Black Rock City, Nev., with a population of 47,000 people in 2007, is a community of performers, musicians, and other artsy, progressive types.

And for 51 weeks out of the year, it doesn't exist.

Burning Man, an eight-day festival, attracts colorful participants from across the globe to the middle of the desert, a patch of barren land about 90 miles northeast of Reno. While the event has a decidedly freewheeling spirit, it does have the Black Rock City Department of Public Works to ensure participants have such amenities as streets and water. The band of DPW staffers plans, surveys, and builds the basic infrastructure of the temporary community. Duties include laying out roads, maintaining potable water systems, and ensuring vendors properly dispose of wastewater.

When the festival wraps on Labor Day, the ad hoc public works department tears down the infrastructure and makes sure festivalgoers remove all of their garbage, erasing all traces of Black Rock City until the next year.